Outside of the fact that the horrific visions seem 100% like MAU fodder, the actual threat of N'zoth feels very real from what little I've done on the PTR, and Ny'alotha looks pretty freaking rad.
It doesn't feel like C'thun where we beat him and then we all go, "Wait? That was a super dangerous threat to the planet?" or Yogg Saron, where they had to retcon him into being more important in Chronicle, a decade after we killed him in the story.